1. Technical Field
The present invention relates to a correcting apparatus, a PDF measurement apparatus, a jitter measurement apparatus, a jitter separation apparatus, an electronic device, a correction method, a program, and a recording medium.
2. Related Art
One known method of measuring jitter included in a signal uses statistical analysis using a probability density function (PDF) or a histogram. For example, a measurement apparatus can calculate a jitter estimate by using a PDF of the transition edge timings of a signal under measurement.
More specifically, the measurement apparatus for calculating a jitter estimate compares a logical value of a signal under measurement with an expected value, at timings designated by a predetermined strobe signal. The measurement apparatus counts the comparison result with an error counter, to calculate a PDF of transition edge timings of the signal under measurement. The measurement apparatus obtains a distribution parameter (e.g. RMS value, or p-p value) of jitter, from the obtained PDF. The measurement apparatus can also calculate estimates of random jitter and deterministic jitter, by curve fitting the PDF using two Gaussian functions.
A variable delay circuit for generating timings at which a strobe signal is generated and an analogue-to-digital converter for controlling the variable delay circuit have non-linearity. Accordingly, the generation timing of the strobe signal becomes non-linear, which is different from the ideal timing. If a PDF is generated by measuring transition edge timings of a signal under measurement using a strobe signal generated at non-linear timings, the resulting PDF will include a measurement error. This causes an error in a distribution parameter of jitter obtained based on the PDF, and further in the estimates of random jitter and deterministic jitter.